JPWO2019155896A1 - Adhesive tape, articles and methods of manufacturing articles - Google Patents

Abstract

An object to be solved by the present invention is to provide an adhesive tape which has adhesiveness at room temperature, can exhibit excellent adhesive force even after heat expansion, and does not require a manufacturing cost. The present invention has an expansive thermosetting adhesive layer (A) that expands due to an external stimulus on at least one surface, and pulls the expansive thermosetting adhesive layer (A) by 180 degrees at 23 ° C. It relates to an adhesive tape having a peeling adhesive strength of 0.1 N / 20 mm or more.

Description

The present invention relates to an adhesive tape having adhesiveness at room temperature and having a structure capable of expanding in the thickness direction thereof.

In general, the adhesive tape can be suitably used when fixing one adherend to a flat surface portion, a curved surface portion, or the like of the other adherend, and is used, for example, an automobile member, an electric device, or the like. Widely used in the manufacturing of various products.

On the other hand, as the range of use of the adhesive tape is expected to expand more and more, the adhesive tape is suitable for fixing the other adherend in the voids of one adherend, for example. It is required to be able to be used for. Specifically, as a motor mounted on a hybrid vehicle or the like, a motor having a configuration in which a magnet is embedded in a predetermined position (void) of a core portion (rotor core) is generally known, and the core portion It has been considered to use the adhesive tape when fixing the magnet in the gap of the magnet.

As an adhesive tape that can be used in the above applications, a thermosetting heat-expandable adhesive tape that expands when heated and fills and fixes a gap between members is known (see, for example, Patent Document 1).

However, since the thermosetting adhesive tape does not have sufficient adhesive strength in the state before heating, the thermosetting adhesive tape is temporarily attached (temporarily adhered) to a predetermined position of the adherend before heating. This is difficult, and in order to temporarily attach the adhesive tape, it is necessary to press the thermosetting adhesive tape to the adherend at a high temperature, which may increase the number of processing steps.
On the other hand, in Patent Document 2, in order to impart initial adhesiveness, an adhesive layer is provided on one surface of the heat-sealing layer, and a non-adhesive heat-sealing layer is provided on the other surface. We are proposing an adhesive tape consisting of at least three layers. However, in this case, there is a problem that the manufacturing cost is higher than that of the conventional single-layer thermosetting adhesive tape.

JP-A-2007-106963 JP 2010-261030

An object to be solved by the present invention is to provide an adhesive tape which has adhesiveness at room temperature, can exhibit excellent adhesive force even after heat expansion, and does not require a manufacturing cost.

The present invention has an expandable thermosetting adhesive layer (A) that expands due to an external stimulus on at least one surface, and pulls the expandable thermosetting adhesive layer (A) by 180 degrees at 23 ° C. It provides an adhesive tape having a peeling adhesive strength of 0.1 N / 20 mm or more.

Since the adhesive tape of the present invention has adhesiveness at room temperature, it can be attached to an accurate position of the adherend even before heating, and causes a deviation in the attachment position of the adhesive tape after temporary attachment. Therefore, the voids of the adherend and the voids between two or more adherends can be sufficiently filled or adhered. Further, since it is not necessary to provide a separate adhesive layer, the manufacturing cost can be reduced.

It is a conceptual diagram which shows the measuring method of a shear adhesive force. This is an example of an embodiment of the present invention. This is an example of an embodiment of the present invention. This is an example of an embodiment of the present invention.

The adhesive tape of the present invention has an swellable thermosetting adhesive layer (A) on at least one surface that expands due to an external stimulus, and the swellable thermosetting adhesive layer (A) at 23 ° C. The 180-degree peeling adhesive strength is 0.1 N / 20 mm or more. The adhesive tape may have the expandable thermosetting adhesive layer (A) as a single layer, or may have two or more layers. When having two or more layers, they may be the same or different. Further, the adhesive tape preferably has the expandable thermosetting adhesive layer (A) on both surfaces, and more preferably is composed of a single layer of the expandable thermosetting adhesive layer (A).
Further, the adhesive tape may have a base material or another adhesive layer (B) in addition to the expandable thermosetting adhesive layer.

The expandable thermosetting adhesive layer (A) expands due to an external stimulus. Examples of the external stimulus include heat and light, and heat is particularly preferable.
The expandable thermosetting adhesive layer (A) includes the expansion rate in the thickness direction of the expandable thermosetting adhesive layer (A) [the expansion thermosetting adhesive layer (A') after heating. Thickness / Thickness of the Expandable Thermosetting Adhesive Layer (A) Before Heating] × 100 is 150% or more. The expansion coefficient is preferably 175% or more, and more preferably 200% to 1000%. In the case of such an adhesive tape, the height (thickness) of the gap between the adherend (C1) or the gap between the adherend (C1) and the adherend (C2) is large. Also, by expanding the adhesive tape, the other adherend can be suitably fixed in the gap, or the gap can be filled with the adhesive tape. Further, with the adhesive tape, even if the surface of the adherend is a rough surface, the other adherend can be suitably fixed to the rough surface.

The expansion rate is based on the thickness of the expandable thermosetting adhesive layer (A) before being left (before expansion) when the adhesive tape is left at a temperature of 50 ° C. to 200 ° C. for 10 minutes. , Refers to the ratio of the thickness of the expanded thermosetting adhesive layer (A') formed by expanding the expandable thermosetting adhesive layer (A) by the leaving.

The thickness of the expandable thermosetting adhesive layer (A) of the adhesive tape is preferably in the range of 10 μm to 250 μm, more preferably in the range of 15 μm to 200 μm, and in the range of 20 μm to 150 μm. This is preferable because a smooth adhesive tape can be produced even if a swelling agent described later is added, and a level of adhesiveness that can be temporarily attached to the adherend can be imparted even before heating.

On the other hand, the thickness of the expanded thermosetting adhesive layer (A') formed by expanding the expandable thermosetting adhesive layer (A) is preferably in the range of 20 μm to 2500 μm, preferably 40 μm. The range of about 1500 μm is preferable in order to obtain even more excellent adhesive strength. Further, the expanded thermosetting adhesive layer (A') preferably has a porous structure.

Further, as the adhesive tape, it is preferable to use a tape in which the thickness of the expandable thermosetting adhesive layer (A) is 10% or more with respect to the total thickness of the adhesive tape, and it is 30%. It is more preferable to use the above-mentioned one because it is easy to fill and preferably fix the adherends (C1) and (C2) having voids.

As described above, the expandable thermosetting adhesive layer (A) has an adhesive strength sufficient to be attached to the adherend (C1) in advance at room temperature (23 ° C.), and the expandable thermosetting adhesive Those capable of filling and adhering the voids of the adherend (C1) or the voids between the adherend (C1) and the adherend (C2) by the pressing force generated by the expansion of the layer (A). use.

As for the adhesive strength of the expandable thermosetting adhesive layer (A), the 180-degree peeling adhesive strength according to JIS Z 0237 is 0.1 N / 20 mm or more at room temperature (23 ° C.). It is preferably 0.3 N / 20 mm or more, and more preferably 0.5 N / 20 mm or more.
It is more preferably 0.75N / 20mm or more, and more preferably 1N / 20mm or more after the adhesive tape is temporarily attached to the adherend (C1), for example, the adherend (C1) and the adherend (C2). ), The adhesive tape attached to the adherend (C1) can be prevented from being caught by the adherend (C2) and rolled up, or the adhesive tape can be prevented from being displaced. , Especially preferable.

As the expandable thermosetting adhesive layer (A), an adhesive composition (a) containing a thermosetting resin or the like, which will be described later, can be used.

As the thermosetting resin, for example, one or more thermosetting tree species selected from urethane resin, phenol resin, unsaturated polyester resin, epoxy resin, acrylic resin and the like can be used. Among them, it is preferable to use an epoxy resin and / or an acrylic resin as the thermosetting resin in order to impart good adhesion to the adherend during heat curing, and it is preferable to use an epoxy resin. Is more preferable in ensuring good heat curability.

The epoxy resin is preferably used in a range of 80% by mass or more with respect to the total amount of the thermosetting resin, and using it in a range of 90% by mass or more preferably fixes the adherend and It is more preferable to secure an adhesive layer in which the change in adhesive strength during heating is small.

Specific examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin and other bisphenol type epoxy resins, dicyclopentadiene-phenol addition reaction type epoxy resin and other dicyclopentadiene type epoxy resins, and biphenyl type. Epoxy resin, tetramethylbiphenyl type epoxy resin, polyhydroxynaphthalene type epoxy resin, isocyanate-modified epoxy resin, 10- (2,5-dihydroxyphenyl) -9,10-dihydro 9-oxa-10-phosphaphenanthrene-10- Oxide-modified epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, triphenylmethane type epoxy resin, tetraphenylethane type epoxy resin, phenol aralkyl type epoxy resin, naphthol novolac type epoxy resin, naphthol aralkyl type epoxy resin, naphthol -Pharmon co-shrink novolak type epoxy resin, naphthol-cresol co-shrink novolak type epoxy resin, aromatic hydrocarbon formaldehyde resin modified phenol resin type epoxy resin, biphenyl-modified novolak type epoxy resin and the like can be used.

Among them, the epoxy resin has an epoxy equivalent of 100 to 450 g / eq, which is liquid at 25 ° C. Epoxy resin (a1), which has a melt viscosity at 150 ° C. of 0.01 dPa · s or more, and an epoxy equivalent of 200 to 2,000 g / eq. It is preferable to use the epoxy resin (a2) which is the above, and using them in combination provides a level of adhesiveness that can be temporarily attached to the adherend even before heating and strong adhesiveness after heating. It is more preferable to achieve both. The melt viscosity at 150 ° C. is a value measured by an ICI viscometer in accordance with ASTM D4287.

The epoxy resin (a1) preferably has a viscosity at 25 ° C. of 1 mPa · s to 2 million mPa · s, more preferably 10 mPa · s to 1.5 million mPa · s, and 30 mPa · s ~. It is more preferably 100,000 mPa · s, and 100 mPa · s to 5000 mPa · s is a level of adhesiveness that can be temporarily attached to the adherend even before heating and strong adhesiveness after heating. It is most preferable to achieve both.

The epoxy resin (a1) is preferably used in the range of 1 to 50% by mass with respect to the total amount of the thermosetting resin, and the adherend is preferably used in the range of 5 to 30% by mass. It is more preferable for fixing to and ensuring a smooth sheet shape before heating.

Examples of the epoxy resin (a1) include bisphenol A type epoxy resin, bisphenol F type epoxy resin and other bisphenol type epoxy resins, 1,6-dihydroxynaphthalene type epoxy resin, t-butylcatechol type epoxy resin, 4,4'. -Diphenyldiaminomethane type epoxy resin, p- or m-aminophenol type epoxy resin, trimethylolpropane type epoxy resin, 1,6-hexanediol type epoxy resin, 1,4-butanediol type epoxy resin, fatty chain modified epoxy Examples include resin.

Further, the epoxy resin (a2) preferably has a melt viscosity at 150 ° C. of 0.01 dPa · s or more, more preferably 0.05 dPa · s to 50 dPa · s, and 0.1 dPa · s. It is more preferably s to 20 dPa · s, and more preferably 0.2 dPa · s to 5.0 dPa · s in order to preferably adjust the expandability of the expandable adhesive layer (A).

The epoxy resin (a2) preferably has a softening point of 10 ° C. to 180 ° C., more preferably 15 ° C. to 150 ° C., and even more preferably 15 ° C. to 100 ° C.20. The temperature of ° C. to 80 ° C. is most preferable for preferably adjusting the expandability of the expandable adhesive layer (A). The softening point is a value measured in accordance with JIS K7234.

The epoxy resin (a2) is preferably used in the range of 5 to 80% by mass with respect to the total amount of the thermosetting resin, and the adherend is preferably used in the range of 10 to 50% by mass. It is more preferable for fixing to and ensuring a smooth sheet shape before heating.

Examples of the epoxy resin (a2) include a dicyclopentadiene type epoxy resin such as an epoxy resin obtained by reacting a bisphenol type epoxy resin with a bisphenol compound, a dicyclopentadiene-phenol addition reaction type epoxy resin, and a polyhydroxynaphthalene type epoxy resin. Triphenylmethane type epoxy resin, isocyanate-modified bisphenol type epoxy resin, 10- (2,5-dihydroxyphenyl) -9,10-dihydro 9-oxa-10-phosphophenanthrene-10-oxide-modified epoxy resin, 2-methoxy Examples thereof include copolymers of naphthalene and orthocresol novolac type epoxy resin, biphenylene type phenol aralkyl resin, phenol aralkyl resin, etc. Among them, dicyclopentadiene type epoxy resin such as dicyclopentadiene-phenol addition reaction type epoxy resin, isocyanate-modified bisphenol. Adhesiveness to use type epoxy resin, 10- (2,5-dihydroxyphenyl) -9,10-dihydro 9-oxa-10-phosphaphenantren-10-oxide modified epoxy resin, triphenylmethane type epoxy resin It is preferable to achieve both heat resistance and heat resistance.

The epoxy resin, together with the epoxy resin (a1) and the epoxy resin (a2), preferably has an epoxy equivalent of 2000 g / eq. As mentioned above, preferably 2000 g / eq. Over 10000 g / eq. The following epoxy resins (a3) can be used in combination.

The epoxy resin (a3) is preferably used in the range of 40 to 95% by mass, preferably 45 to 94% by mass, and 50 to 93% by mass with respect to the total amount of the thermosetting resin. It is preferable to use it in the range of%, preferably in the range of 55 to 92% by mass, preferably in the range of 60 to 91% by mass, and preferably in the range of 65 to 90% by mass. , It is more preferable to secure a smooth sheet shape before heating.

Further, as the expandable thermosetting adhesive layer (A), it is preferable to use one containing a curing agent capable of reacting with the thermosetting resin.

As the curing agent, for example, when an epoxy resin is used as the thermosetting resin, it is preferable to use one having a functional group capable of reacting with the epoxy group.

The curing temperature of the thermosetting material is preferably equal to or higher than the expansion temperature of the leavening agent described later, and the curing time is preferably equal to or longer than the expansion time. As a result, the leavening agent can be sufficiently expanded in the thermosetting material softened by heating, and the sheet thickness after expansion can be made uniform.

Examples of the curing agent include amine compounds, amide compounds, acid anhydride compounds, and phenol compounds. For example, as the amine compound, diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, imidazole derivative, BF3-amine complex, guanidine derivative and the like can be used.

Examples of the amide compound include a polyamide resin synthesized from a dimer of dicyandiamide and linolenic acid and ethylenediamine, and examples of the acid anhydride compound include phthalic anhydride, trimellitic anhydride and anhydrous. Examples thereof include pyromellitic acid, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, and the like. Examples of the phenolic compound include phenol novolac. Resin, cresol novolac resin, aromatic hydrocarbon formaldehyde resin modified phenol resin, dicyclopentadienephenol addition type resin, phenol aralkyl resin (Zyroc resin), naphthol aralkyl resin, trimethylolmethane resin, tetraphenylol ethane resin, naphthol novolac resin , Naftor-phenol co-condensed novolak resin, naphthol-cresol co-condensed novolak resin, biphenyl-modified phenolic resin (polyvalent phenol compound with phenol nuclei linked by bismethylene group), biphenyl-modified naphthol resin (phenol nuclei linked by bismethylene group) Polyvalent naphthol compound), aminotriazine-modified phenolic resin (compound having a phenol skeleton, triazine ring and primary amino group in its molecular structure) and alkoxy group-containing aromatic ring-modified novolak resin (formaldehyde containing phenol nucleus and alkoxy group) Examples thereof include polyvalent phenol compounds such as polyvalent phenol compounds in which rings are linked).

The curing agent is preferably used in the range of 1 part by mass to 60 parts by mass with respect to a total of 100 parts by mass of the thermosetting resin such as the epoxy resin, and is used in the range of 5 parts by mass to 30 parts by mass. It is preferable to do so.

Further, as the thermosetting material, a material containing a curing accelerator can be used. As the curing accelerator, a phosphorus compound, an amine compound, an imidazole derivative or the like can be used. When the curing accelerator is used, the amount used is preferably 0.1 part by mass to 5 parts by mass, and 0.5 parts by mass with respect to 100 parts by mass in total of the thermosetting resin such as the epoxy resin. More preferably, it is in the range of ~ 3 parts by mass.

As the curing agent and curing accelerator, it is preferable to use powdery ones. Since the powdery curing accelerator suppresses the thermosetting reaction at a low temperature as compared with the liquid curing accelerator, the storage stability of the thermosetting material before the thermosetting at room temperature is further improved. Can be improved.

Further, as the expandable thermosetting adhesive layer (A), when the expandable thermosetting adhesive layer (A') composed of the thermosetting product is used in an environment where the temperature changes greatly. Even if there is, a material containing a thermoplastic resin can be used as long as the fixing property of the joint is not impaired.

Examples of the thermoplastic resin include urethane resins such as polyurethane (PU) and thermoplastic polyurethane (TPU); polycarbonate (PC); polyvinyl chloride (PVC), vinyl chloride-vinyl acetate copolymer resin and the like. Based resin: Acrylic resin such as polyacrylic acid, polymethacrylic acid, methyl polyacrylate, polymethylmethacrylate (PMMA), polyethyl methacrylate; polyethylene terephthalate (PET), polybutylene terephthalate, Polyester resins such as polytrimethylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate; polyamide resins such as nylon (registered trademark); polystyrene (PS), imide-modified polystyrene, acrylonitrile-butadiene. Polystyrene resin such as styrene (ABS) resin, imide-modified ABS resin, styrene / acrylonitrile copolymer (SAN) resin, acrylonitrile / ethylene-propylene-diene / styrene (AES) resin, polyethylene (PE) resin, polypropylene (PP) Olefin-based resins such as resins and cycloolefin resins; cellulose-based resins such as nitrocellulose and cellulose acetate; silicone-based resins; thermoplastic resins such as fluororesins, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, vinyl chloride-based Thermoplastic elastomers such as thermoplastic elastomers, urethane-based thermoplastic elastomers, ester-based thermoplastic elastomers, and amide-based thermoplastic elastomers can be used.

For the above reasons, the thermoplastic resin is preferably used in the range of 1 part by mass to 100 parts by mass with respect to 100 parts by mass of the thermosetting resin.

In addition to the above-mentioned thermosetting materials, for example, fillers, softeners, stabilizers, adhesion promoters, leveling agents, antifoaming agents, plasticizers, etc., as long as the effects of the present invention are not impaired. Adhesive-imparting resins, fibers, antioxidants, ultraviolet absorbers, antioxidants, thickeners, colorants such as pigments, and additives such as fillers can be used.

The curing agent and curing accelerator are preferably used before the thermosetting material is thermally cured or before being molded into a sheet or the like.

As the swelling agent that may be contained in the swellable thermosetting adhesive layer (A), an swelling agent capable of forming a porous structure as the swellable heat-curable adhesive layer (A') after expansion is used. Is preferable, for example, inorganic compounds such as ammonium carbonate, ammonium hydrogencarbonate, ammonium nitrite, ammonium hydride, azide, alkane fluoride such as trichloromonofluoromethane, azo compounds such as azobisisobutyronitrile, and paratoluenesulfonyl hydrazine. Hydrazine compounds such as, semicarbazide compounds such as p-toluenesulfonyl semicarbazide, triazole compounds such as 5-morpholyl-1,2,3,4-thiatriazole, N-nitroso compounds such as N, N'-dinitrosoterephthalamide. Can be used.

Further, as the leavening agent, for example, an expandable capsule in which a hydrocarbon solvent is microencapsulated can be used. The above-mentioned leavening agent can be used alone or in combination of two or more.

As the leavening agent, among the above, using an expandable capsule in which a hydrocarbon solvent is microencapsulated prevents deterioration of the expansion thermosetting adhesive layer (A) due to the influence of heat or the like, for example. More preferable.

Further, it is preferable to use a leavening agent that can expand at a temperature around the softening point of the expandable thermosetting adhesive layer (A) because the adhesive tape can be sufficiently expanded. ..

Examples of commercially available expandable capsules include Expandel (manufactured by Nippon Phillite Co., Ltd.), Matsumoto Microsphere (manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd.), and Microsphere (manufactured by Kureha Corporation). As the inflatable capsule, it is preferable to use a capsule having a volume (volume expansion coefficient) of 8 to 60 times after expansion with respect to the volume of the capsule before expansion.

The amount of the swelling agent used, preferably the amount of the heat-expandable capsule used, is from 0.3 part by mass to 100 parts by mass with respect to 100 parts by mass of the solid content of all the components of the swellable thermosetting adhesive layer (A). The range of 30 parts by mass is preferable, the range of 0.5 parts by mass to 25 parts by mass is more preferable, and the range of 1 part by mass to 20 parts by mass fills the voids of the adherend. It is more preferable because it can expand sufficiently to equalize and obtain even better adhesive force.

Further, as the adhesive tape of the present invention, as described above, in addition to the expandable thermosetting adhesive layer (A), a base material or another adhesive layer (B) can be provided. As the adhesive layer (B) constituting the adhesive tape, an adhesive composition (b) capable of forming an adhesive or adhesive layer can be used.

The adhesive layer (B) includes the expansion coefficient in the thickness direction of the adhesive layer (B) [the thickness of the adhesive layer (B) after being left to stand after heating / the adhesive layer before being left to stand (the adhesive layer (B)). B) thickness] × 100 is 120% or less. The expansion coefficient of the adhesive layer (B) is preferably 115% or less, and more preferably 110% or less. With such an adhesive tape, excellent adhesive force to the adherend can be maintained even after the expandable thermosetting adhesive layer (A) has expanded. The expansion rate of the adhesive layer (B) is based on the thickness of the adhesive layer (B) before being left when the adhesive tape is left in an environment of 50 ° C. to 200 ° C. for 10 minutes. It refers to the ratio of the thickness of the adhesive layer after being left to stand.

The thickness of the adhesive layer (B) is preferably in the range of 1 μm to 150 μm, and preferably in the range of 5 μm to 100 μm, which is the expandable thermosetting adhesive layer (A) constituting the adhesive tape. Expands to fill the voids of the adherend (C1) or the voids between the adherend (C1) and the adherend (C2), and the adhesive layer (B) fills the gap between the adherend (C1). It is more preferable because it can exhibit excellent adhesive strength when attached to C2).

Since the adhesive layer (B) preferably has a low expansion coefficient as described above, a leavening agent exemplified as one that can be used when forming the expandable thermosetting adhesive layer (A) is substantially used. It is preferable that it is not contained in. As the adhesive layer (B), for example, an adhesive composition (b) containing a resin such as a thermosetting resin or a thermoplastic resin and having a low or no content of the leavening agent is preferably used. Can be done.

As the resin that can be used for the adhesive composition (b), a conventionally known resin can be selected and used. Among them, as the resin, a resin containing an adhesive composition (a) that can be used, for example, for forming the thermosetting adhesive layer (A) in order to improve the production efficiency of the adhesive tape of the present invention. It is preferable to use the same one as the one exemplified as.

As the adhesive composition (b), for example, one containing a resin such as the above-mentioned thermosetting resin or thermoplastic resin and, if necessary, an additive such as a tackifier or a cross-linking agent can be used. it can.

The tackifier resin includes, for example, a rosin-based tackifier resin, a polymerized rosin-based tackifier resin, a polymerized rosin ester-based tackifier resin, and a rosinphenol for the purpose of adjusting the strong adhesiveness of the adhesive layer (B). A system adhesive resin, a stabilized rosin ester adhesive resin, a disproportionate rosin ester adhesive resin, a terpene adhesive resin, a terpene phenol adhesive resin, a petroleum resin adhesive resin, etc. can be used. ..

As the cross-linking agent, known isocyanate-based cross-linking agents, epoxy-based cross-linking agents, aziridine-based cross-linking agents, polyvalent metal salt-based cross-linking agents, and metal chelates are used for the purpose of improving the cohesive force of the adhesive layer (B). A system-based cross-linking agent, a keto-hydrazide-based cross-linking agent, an oxazoline-based cross-linking agent, a carbodiimide-based cross-linking agent, a silane-based cross-linking agent, a glycidyl (alkoxy) epoxysilane-based cross-linking agent, and the like can be used.

As the additive, if necessary, a base (such as aqueous ammonia) or an acid for adjusting the pH, an adhesion accelerator, a stabilizer, a foaming agent, a plasticizer, etc., as long as the desired effect of the present invention is not impaired. Softeners, antioxidants, glass or plastic fibrous, balloon-like, bead-like, metal powder-like fillers, pigments, colorants such as dyes, UV absorbers, antioxidants, pH adjusters, coatings Known agents such as formation aids, leveling agents, thickeners, water repellents, and defoaming agents can be used.

As the adhesive composition (b), one containing a solvent can be used in order to maintain good coating workability and the like. As the solvent, for example, toluene, xylene, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, hexane and the like can be used. When the water-based adhesive composition is used as the adhesive composition (b), water or an aqueous solvent mainly composed of water can be used as the solvent.

The adhesive tape of the present invention is produced, for example, by subjecting the adhesive composition (a) to a release liner and drying it to form an expandable thermosetting adhesive layer (A) [I]. can do.

Among the adhesive tapes of the present invention, the adhesive tape composed of the expandable heat-curable adhesive layer (A) and the adhesive layer (B) is described in the step [I] and the step [I]. Separately, the step [II] of forming the adhesive layer (B) by applying the adhesive composition (b) to the release liner and drying or the like, and the expandable thermosetting adhesive layer (A). It can be manufactured by transferring the adhesive layer (B) to one side of the surface and performing a step [III] of crimping them.
It is preferable that the expandable thermosetting adhesive layer (A) does not substantially expand in the process of manufacturing the adhesive tape.

Further, as the adhesive tape of the present invention, if necessary, a non-woven fabric layer, a resin film layer, or a layer made of metal (Z) between the expandable thermosetting adhesive layer (A) and the adhesive layer (B). ) Can be used. Since such an adhesive tape has good rigidity, it is excellent in sticking workability.

The layer (Z) is, for example, a non-woven fabric, preferably made of pulp, rayon, Manila hemp, acrylonitrile, nylon, polyester, or the like, and a papermaking step is required to satisfy the tensile strength of the non-woven fabric. A one-step impregnation treatment in which polyamide is added and coated after drying, or a two-step impregnation treatment using viscose or a thermoplastic resin as a binder may be performed. The resin film is a resin film layer formed by using a plastic film such as a polyester film, a polyethylene film, a polypropylene film, a polyvinyl chloride film, or a polyimide film, and the metal layer is a metal layer such as aluminum or copper. Can be mentioned.

As the layer (Z), it is preferable to use a layer having a thickness of 1 μm to 200 μm.

The adhesive tape having the layer (Z) is formed by, for example, applying the adhesive composition (a) to a release liner and drying it to form an expandable thermosetting adhesive layer (A). Separately from the step [I], the step [II] of forming the adhesive layer (B) by applying the adhesive composition (b) to a release liner and drying or the like, the expandable thermosetting adhesion. A step [IV] of laminating the layer (Z) on one side of the agent layer (A), and a step of transferring the adhesive layer (B) onto the surface composed of the layer (Z) and pressing them together [ It can be manufactured by passing through V].

In the present invention, by using an adhesive tape that has initial adhesiveness, expands by giving a stimulus, and has excellent adhesive strength even after expansion, for example, it is adhered. An article having a gap between the body (C1) or the adherend (C1) and the adherend (C2) is preferably used in the production of an article in which the gap is filled or adhered with the adhesive tape. be able to.

As a method for producing the article, the step [1] of attaching the expandable heat-curable adhesive layer (A) constituting the adhesive tape to the portion (c1-1) constituting the adherend (C1), described above. In the step of applying a stimulus to the expansive thermosetting adhesive layer (A) [2], the expansive thermocurable adhesive layer (A) expands due to the stimulus, and the expansive thermocurable adhesive layer (A') The step [3] in which the adhesive layer is formed, and the expanded thermosetting adhesive layer (A') or the adhesive layer (B) constituting the adhesive tape is another portion constituting the adherend (C1). A gap in the adherend (C1) having a step [4] attached to (c1-2) or another adherend (C2), or an adherend (C1) and an adherend (C2). Examples thereof include a method of manufacturing an article in which a gap between the two is adhered or filled through an expanded material of an adhesive tape.

In the step [1], the heat-curable adhesive layer (A) of the adhesive tape is pressure-bonded to the portion (c1-1) constituting the adherend (C1) with a force of 0.1 N / cm ² or more. However, the adhesive force of the adhesive tape to the portion (c1-1) constituting the adherend (C1) is increased, and the displacement between the adhesive tape and the adherend (C1) can be suppressed even before heating. preferable. The adhesive tape of the present invention has adhesiveness at room temperature, but if higher adhesiveness is required, the adhesive tape may be warmed and attached to the adherend (C1). At this time, the temperature for warming the adhesive tape is preferably room temperature (23 ° C.) or higher and 100 ° C. or lower, and 80 ° C. or lower expands the expandable thermosetting adhesive layer (A) or deforms the shape of the adhesive tape. It is more preferable because it can be crimped to the adherend without causing it.

When the expandable thermosetting heat-expandable adhesive layer (A) or the adhesive layer (B) of the adhesive tape is pressure-bonded to the portion (c1-1) constituting the adherend (C1). If necessary, equipment such as a press machine and a roller may be used, or they may be pressed with a finger.

In the step of stimulating the expandable thermosetting adhesive layer (A) in the step [2], the stimulus is preferably heat. Among them, the heating temperature is preferably, for example, a temperature corresponding to the temperature at which the leavening agent expands (expansion start temperature), specifically, preferably 50 to 200 ° C, more preferably 60 to 190 ° C. It is preferable that the temperature is 70 to 180 ° C. because it is excellent in stability during storage, the adhesive tape can be sufficiently expanded, and excellent adhesive force can be obtained after expansion.

Examples of the heating method include a method of putting an article into a heating device such as an oven or a heating furnace to heat the entire article, the expandable thermosetting adhesive layer (A), the adhesive tape, or the adhesion. A method of heating the expansive thermosetting adhesive layer (A) by bringing a heat source into contact with or approaching the body can be mentioned. As the heat source, for example, a halogen lamp, a laser irradiation device, an electromagnetic induction heating device, a hot stamp, a hot plate, a soldering iron and the like can be used. The heating method can be selected according to the size of the article.

In the step [4], the expansion thermosetting adhesive layer (A') or the adhesive layer (B) is subjected to the force generated by expanding the expandable thermosetting adhesive layer (A). The other portion (c1-2) or another adherend (C2) constituting the adherend (C1) is crimped. Therefore, when filling the voids of the adherend (C1) or the voids between the adherend (C1) and the adherend (C2), it is necessary to apply pressure using, for example, a press. Absent. Further, since the adhesive tape and the adherend are brought into close contact with each other by the force generated by the expansion, even when an adherend having irregularities on the surface (having a rough surface) is used, the adhesive tape It is difficult for a gap to be formed between the and the adherend. Examples of the adherends (C1) and (C2) include plastics made of metal such as glass, aluminum, stainless steel and copper, and resins such as acrylic, polycarbonate and polyimide. As the adherends (C1) and (C2), those having the same material and shape may be used, or those having different materials and shapes may be used. As the adherends (C1) and (C2), the surface in contact with the expandable thermosetting adhesive layer (A) or the adhesive layer (B) may be a rough surface.

The surface shape of the adherend (C1), the expansive thermosetting adhesive layer (A) of the adherend (C2), and the adhesive layer (B) in contact with the adherend is, for example, the surface of the adherend. There may be minute irregularities of 1 μm or less, irregularities of 1 μm or more such as embossing or printing steps, and warpage or distortion of the adherend itself. The unevenness is preferably 500 μm or less, more preferably 400 μm or less, further preferably 300 μm or less, and the difference between the highest point and the lowest height with respect to the plane is the warp and strain of the adherend itself. It is preferably 500 μm or less, more preferably 400 μm or less, and 300 μm or less occurs when the expandable thermosetting adhesive layer (A) is expanded in the steps [2] to [4]. Good adhesiveness can be obtained by pressure. Further, the adherend may be a combination of curved surfaces, the curved surfaces may have the same radius of curvature, or the curved surfaces may have different radii of curvature. The radius of curvature is in the range of 0.1 mm to 10 m due to the pressure generated when the expandable thermosetting adhesive layer (A) is expanded in the steps [2] to [4]. Good adhesiveness can be obtained. When the radius of curvature of the adherends is different, the gap formed between the adherends is preferably 500 μm or less, more preferably 400 μm or less, and 300 μm or less in the step [2]. ] To [4], good adhesiveness can be obtained by the pressure generated when the expandable thermosetting adhesive layer (A) is expanded.

The shapes of the adherend (C1) and the adherend (C2) are not particularly specified, and examples thereof include a two-dimensional shape, a three-dimensional shape (curved surface, etc.), a shape having surface irregularities, a shape to be fitted, and the like. Be done. A combination of the above shapes may be used.

As a method for producing the article, the steps [1], [2], and [3] are performed in this order, which has excellent adhesive strength before heating, is expandable by heating, and is heated. It is preferable for exhibiting excellent adhesive strength even after expansion. In particular, when the surface of the adherend (C1) or (C2) is rough, it is effective in exhibiting good adhesive strength.

Examples of the article obtained by the above method include a small motor mounted on a moving part of an automobile. The motor is usually composed of an exterior member (cylindrical member) and a lid-shaped member thereof. Specific examples of the motor include a motor in which a metal tubular member and a resin lid-shaped member having a shape corresponding to the tubular member are fixed in a fitted state. The adhesive tape of the present invention can fill a gap that may be formed between the tubular member and the lid-like member.
Further, the adhesive tape of the present invention can be used for fixing a housing to a display panel of a mobile phone, a smartphone, a tablet, a television, an in-vehicle navigation system or the like.
Further, the adhesive tape of the present invention can be used for fixing a thin film sheet to an uneven adherend while maintaining a smooth state. A specific example is the fixing of the substrate and the reflective sheet in the direct type LED light emitting device. The substrate surface of the light emitting device is coated with resist ink, and if the reflective sheet is fixed with tape so as to follow the unevenness of the ink layer, the reflective sheet undulates and the optical characteristics are not exhibited. It is preferable to use the adhesive tape of the present invention because the reflective sheet can be smoothly fixed while the tape follows the unevenness of the resist ink layer.

Examples and comparative examples will be specifically described below.

(Preparation Example 1)
Epoxy resin 1 (epoxy equivalent 403 g / eq., Liquid (25 ° C.), viscosity 1.4 million mPa · s (25 ° C.)) in 7.0 parts by mass, epoxy resin 2 (epoxy equivalent 162 g / eq., Solid (25 ° C.)) ), Melt viscosity at 150 ° C., softening point 25 ° C., 28 parts by mass, epoxy resin 3 (epoxy equivalent 8,000 g / eq., Solid (25 ° C.), softening point 200 ° C. or higher) methyl ethyl ketone solution (Solid content 30% by mass) 216.7 parts by mass, curing agent (2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s-triazine isocyanuric acid adduct) 2.0 A thermosetting resin composition (X-1) was prepared by mixing parts by mass.

(Preparation Example 2)
Except for changing the epoxy resin 1 from 7 parts by mass to 2 parts by mass and using 5 parts by mass of epoxy resin 4 (epoxy equivalent 130 g / eq., Liquid (25 ° C.), viscosity 300 mPa · s (25 ° C.)). , A thermosetting adhesive composition (X-2) was obtained in the same manner as in Preparation Example 1.

(Preparation Example 3)
Same as Preparation Example 1 except that the amount of the methyl ethyl ketone solution (solid content 30% by mass) of the epoxy resin 3 used is changed from 216.7 parts by mass to 166.7 parts by mass and 15 parts by mass of the epoxy resin 4 is used. The thermosetting adhesive composition (X-3) was obtained by the above method.

(Preparation Example 4)
Preparation example except that 28 parts by mass of epoxy resin 5 (epoxy equivalent 275 g / eq., Melt viscosity 27 dPa · s at 150 ° C., solid (25 ° C.), softening point 101 ° C.) is used instead of epoxy resin 2. A thermosetting adhesive composition (X-4) was obtained in the same manner as in 1.

(Example 1)
051 DU40 (thermally expanded microcapsules manufactured by Nippon Philite Co., Ltd., expansion start temperature 108 to 113 ° C.) was added to the thermosetting adhesive composition (X-1) obtained in Preparation Example 1 as a swelling agent. An expandable thermosetting adhesive composition (expandable thermosetting adhesive composition) by adding 15 parts by mass with respect to 100 parts by mass of the solid content of the thermosetting resin contained in the resin composition (X-1) and stirring for 10 minutes using a dispersion stirrer. Y-1) was obtained.

Next, the expandable thermosetting adhesive composition (Y-1) was applied to a rod-shaped metal on the surface of a release liner (one side of a polyethylene terephthalate film having a thickness of 50 μm was peeled off with a silicone compound). Using an applicator, coating was performed so that the thickness after drying was 50 μm.

Next, the coated product was put into a dryer at 85 ° C. for 5 minutes and dried to obtain a sheet-shaped expandable thermosetting adhesive layer (Z-1) having a thickness of 50 μm.

(Example 2)
A sheet-like expandable thermosetting adhesive layer having a thickness of 50 μm (in the same manner as in Example 1 except that the thermosetting adhesive composition (X-2) obtained in Preparation Example 2 was used. Z-2) was obtained.

(Example 3)
A sheet-shaped expandable thermosetting adhesive layer having a thickness of 50 μm (in the same manner as in Example 1 except that the thermosetting adhesive composition (X-3) obtained in Preparation Example 3 was used. Z-3) was obtained.

(Comparative Example 1)
A sheet-shaped expandable thermosetting adhesive layer having a thickness of 50 μm (in the same manner as in Example 1 except that the thermosetting adhesive composition (X-4) obtained in Preparation Example 4 was used. Z-4) was obtained.

[Measuring method of expansion coefficient of adhesive tape]
The thickness of the adhesive tape produced in Examples 1 to 3 and Comparative Example 1 was measured using a thickness gauge. Next, the adhesive tape was expanded by leaving it in an environment of 130 ° C. for 10 minutes, and the thickness of the expanded adhesive tape was measured using a thickness gauge.

The expansion rate was calculated by the following formula as the ratio of the adhesive tape after being left to the thickness of the adhesive tape before being left in an environment of 130 ° C. for 10 minutes (before expansion). ..
[Thickness of the adhesive tape after being left (after expansion) / Thickness of the adhesive tape before being left (before expansion)] × 100

[Measurement method of initial adhesive strength of thermosetting adhesive layer]
The 180 degree peeling adhesive strength was measured according to JIS Z 0237. The release paper on one side of the adhesive tape was peeled off and lined with a polyethylene terephthalate film having a thickness of 25 μm. At this time, in order to prevent the adhesive tape from falling off from the polyethylene terephthalate, the adhesive tape and the polyethylene terephthalate were bonded together and pressure-bonded at 60 ° C. for 1 minute with a load of 1 kN.
The backed adhesive tape was sufficiently allowed to cool at 23 ° C., cut into a width of 10 mm, the release liner on the other side of the adhesive tape was peeled off, and the adhesive layer was degreased on a SUS plate to have a smooth surface. A test piece was obtained by adhering to a sheet and reciprocating once with a 2 kg roller.
The test piece was left to stand in an environment of 23 ° C. for 1 hour, and then the adhesive tape constituting the test piece was applied to the test piece in the same environment using a Tensilon tensile tester [manufactured by A & D Co., Ltd., model: RTM-100]. The adhesive force when peeled from the SUS plate in the 180 degree direction at a speed of 300 mm / min was measured.

[Initial adhesiveness evaluation of expandable thermosetting adhesive layer]
The adhesive tapes prepared in Examples 1 to 3 and Comparative Example 1 were cut into squares of 10 mm × 10 mm. The cut adhesive tape was peeled off from the release film at 23 ° C. and attached to a degreased SUS plate having a width of 50 mm, a length of 70 mm and a thickness of 2 mm.
Then, the SUS plate was erected at 90 ° to the floor at 23 ° C., and the SUS plate was lifted and dropped vertically so that the adhesive tape attached to the SUS plate was 10 cm in height from the floor. This was repeated 10 times, and the one in which the adhesive tape was not displaced was designated as “◯”, and the one in which the adhesive tape was displaced was designated as “x”.

[Measurement method of shear adhesive strength]
Two aluminum plates with a width of 15 mm, a length of 70 mm, and a thickness of 0.5 mm are degreased and applied to the end of the upper surface (C1-1) of one of the aluminum plates (C1) as shown in FIG. Two spacers were arranged in parallel with a gap of 12 mm and bonded. The spacer used was prepared so that the total thickness of the adhesive tape used for bonding with the spacer was 50 μm thicker than the total thickness of the adhesive tape.
Next, an adhesive tape cut to a size of 10 mm × 10 mm is attached on the upper surface (C1-1) side of the aluminum plate (C1) and between the two spacers, and a 2 kg hand roller is attached. It was crimped using. Next, another aluminum plate (C2) (width 15 mm × length 70 mm × thickness 0.5 mm) having a smooth surface treated with degreasing was placed on the upper surface of the adhesive tape, and these were fixed with clips. The fixed product was heated at 130 ° C. for 30 minutes and then left to cool in an environment of 23 ° C. for 30 minutes. Next, the one from which the clip was removed was used as a test piece, and the ends of the two aluminum plates were chucked, respectively, and 180 degrees using a Tensilon tensile tester [manufactured by A & D Co., Ltd., model: RTM-100]. The adhesive force in the shear direction when the tensile test was performed at 10 mm / min in the direction was measured.

1 Aluminum plate (C1)
2 Aluminum plate (C2)
3 Spacer 4 Adhesive tape of the present invention 5 Air gap between the adhesive tape of the present invention and the aluminum plate (c2) 6 Expandable thermosetting adhesive layer 7 Adhesive layer 8 Base material

Claims (10)

At least one surface has an expansive thermosetting adhesive layer (A) that expands due to an external stimulus, and the expansive thermosetting adhesive layer (A) has a 180-degree peeling adhesive force at 23 ° C. Adhesive tape of 0.1N / 20mm or more. The adhesive tape according to claim 1, wherein the stimulus is heat. Expansion rate in the thickness direction of the expandable thermosetting adhesive layer (A) [Thickness of the expanded thermosetting adhesive layer (A') after heating / the expandable thermosetting adhesive layer before heating ( A) Thickness] × 100 is 150% or more of the adhesive tape according to claim 1 or 2. Any one of claims 1 to 3, wherein the expandable thermosetting adhesive layer (A) is a layer containing a thermosetting resin and a thermal expansion capsule having an expansion start temperature in the range of 50 ° C. to 200 ° C. The adhesive tape according to item 1. The adhesive tape according to any one of claims 1 to 4, which has the expandable thermosetting adhesive layer (A) on both surfaces. The adhesive tape according to any one of claims 1 to 5, which is composed of a single layer of the expandable thermosetting adhesive layer (A). An adhesive composition in which the expandable thermosetting adhesive layer (A) contains one or more thermosetting resins selected from urethane resin, phenol resin, unsaturated polyester resin, epoxy resin and acrylic resin. The adhesive tape according to any one of claims 1 to 6, wherein (a) is used. The invention according to any one of claims 1 to 7, which is used for filling the voids of the adherend (C1) or the voids between the adherend (C1) and the adherend (C2). Adhesive tape. The expanded product of the adhesive tape according to any one of claims 1 to 8, wherein the gap of the adherend (C1) or the gap between the adherend (C1) and the adherend (C2) is Articles glued or filled through. The step [1] of attaching the adhesive tape according to any one of claims 1 to 8 to the portion (c1-1) constituting the adherend (C1), the expandable thermosetting adhesive layer ( A step of applying a stimulus to A) [2], a step of expanding the expandable thermosetting adhesive layer (A) by the stimulus to form an expanded thermosetting adhesive layer (A') [3]. Then, the expanded thermosetting adhesive layer (A') constituting the adhesive tape is attached to another site (c1-2) or another adherend (C2) constituting the adherend (C1). The gap between the adherend (C1) or the gap between the adherend (C1) and the adherend (C2) having the step [4] is any one of claims 1 to 8. A method for producing an article bonded or filled through an inflatable material of an adhesive tape according to.

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